While turn signal cancellation controls are well known, the present invention provides for improvements and enhancements over existing turn signal control strategies by providing for, among other things, controls that allow the driver to select between traditional and more advanced turn signal control feature. An example of such an advanced feature is the placement of a control lever in a position to effect signaling that will cancel when the steering wheel of the vehicle is detected to have returned to a neutral position from the direction for which the turn signal was activated. For example, a steering wheel execution of a right or left turn and subsequent return to a neutral or generally straight ahead alignment of the steering mechanism acts to cancel the turn signal. A further advanced turn signal mode is also provided that allows the driver to actuate a turn signal control that is sustained or locked as active until released by the driver.
When the driver selects the turn signal mode that provides for self/auto cancellation, further aspects of the present invention, including the specially tailored control strategies are implemented. The execution of turns and lane changes, especially by commercial vehicles of the nature of semi tractor trailer trucks, must be carefully made to appropriately accommodate the lengths of these vehicles. For safety, such turns must be signaled throughout the maneuver to assure awareness of other motorists. For driver convenience as well as safety, appropriate self/auto cancellation of the turn signal is a beneficial feature in that it relieves the driver of having to remember to disengage the executed signal and further prevents an unintended continuation of the signal for a prolonged period of time should the driver fail to disengage signal actuation.
The present invention meets these and other desired safety and convenience criteria by first providing means to effect activation of the self/auto cancellation mode of the turn signals by the driver. The self/auto cancellation is further implemented vis-à-vis computer-based control strategies that take into account vehicle speed and the degree by which the vehicle steering mechanism (steering wheel) is turned after a particular signaling mode is set. The time period that the steering wheel is allowed to return to the steering-neutral (straight ahead wheel alignment) position is also monitored as a threshold input for terminating the signaling sequence.
Importantly for both safety and driver convenience aspects, the selected turn signal mode of self/auto cancellation can as well be deactivated and the signaling routine cancelled manually by the driver by returning the selector control to the turn signal neutral position.
When the driver selects the maintained or locked turn signal position, the affected turn signal remains activated until manually deactivated by the driver by returning the turn signal selector to the neutral position. This mode can be contrasted with passenger vehicles which usually cancel signaling after the steering wheel has been turned a certain amount in the signaled direction and then allowed to resume the neutral position. This is not suitable in larger commercial vehicles, however, due to the wider range of steering wheel manipulation that is required, for instance, just to maintain course or when affecting a turn.